You know, this reminds me of a story, it was by 343 Salty Beans; anyway, let's see is you can beat his story.
First off, you need to use the code. You can find out about the code by visiting the link marked "Direction for use of the Fan Fiction submision form" at the bottom of this post. Now as for the Spartans, I don't think that you got their attitudes quite right. You made them sound more like Marines that Spartan soldiers. Some of the details were off, like when is the last time you saw a safty on an M41 Light Anti-aircraft Gun? Your details were ok for the most part, though you might try to enhance them at parts. I see you are making this a MP based thing, as you have names other than their own to describe them. This is ok, but it would not be preferable to try to incorperate this into the main Halo-verse storyline. Just keep it MP.